package com.pdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {

    // 初始时间2025.1.1 0:0:0
    private static final long BEGIN_TIMESTAMP = 1735689600L;
    // 左移位数
    private static final long COUNT_BITS = 32;

    private StringRedisTemplate stringRedisTemplate;
    public RedisIdWorker(StringRedisTemplate stringRedisTemplate){
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public long nextId(String keyPrefix){
        // 1.生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;

        // 2.生成序列号
        // 2.1 获取当前日期，精确到天
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        // 2.2 自增长
        long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);
        // 3.拼接并返回

        return timestamp << COUNT_BITS | count;
    }

}
